Ask Me Help Desk - Faulty air admittance valve?

Faulty air admittance valve?

I own a manufactured home new in 2006. We are on city sewer and water. We have had problems with the check valve (air admittance valve) under the sinks. 2 have failed and let in sewer smell. Once the valve is changed the smell usually goes away. I changed the one under our master bath sink and the smell is still there. I have run drain cleaner down the double sinks and shower. There have never been any clogs. Could this new check valve be faulty or may there be another problem? How long do these valves usually last?
Thanks so much!

Rrep: I have never seen AAV to fail. But I am not saying it is not possible to happenl. You have two AAV that failed in one house. Maybe you should look different direction, like sewage under the house, floor drain, jac. Tub drain, absence of P-traps, etc...

Quote:

Originally Posted by Milo Dolezal

Rrep: I have never seen AAV to fail. But I am not saying it is not possible to happenl. You have two AAV that failed in one house. Maybe you should look different direction, like sewage under the house, floor drain, jac. tub drain, absence of P-traps, etc.....

The one I replaced in my daughter's bathroom did work. I have now replaced the valve in my master bath with 2 different AAV and I still smell the sewer smell under the cabinet. It is quite strong. Should this work immediately at stopping the smell? What next?
Thanks!

Properly working AAV will stop sewer odor entering your room immediately. Then, you have to vent out the smell that was there for few days. Try to spray air refresher into the cabinet and see if the smell returns.

Quote:

Originally Posted by Milo Dolezal

Properly working AAV will stop sewer odor entering your room immediately. Then, you have to vent out the smell that was there for few days. Try to spray air refresher into the cabinet and see if the smell returns.

One of the new AAV I used made the smell 10 times worse. After 2 hours of that I put another on and it isn't as strong in the room. I have a fan on and windows open. When I run water, I can't smell anything. It is after nothing is running. The smell seems to get worse as it sits. I know it is working because I could hear it click after running water and flushing the toilet. If this evening the smell is still strong from the cabinet, is there anything else I could check? What else could be the problem? We are the original owners and have lived here 2 years before anything like this happened.
Again, thanks for all your advice.

Ok, my question to you is: Do you have P-trap under the sink? ( P-trap is the bend that looks like "J" )

Quote:

Originally Posted by Milo Dolezal

Ok, my question to you is: Do you have P-trap under the sink ?? ( P-trap is the bend that looks like "J" )

Yes, the pipe comes down from the drain like a "J' then loops back over to another pipe. This other pipe goes upward and that is where the AAV is located. I can provide a picture.

Quote:

Originally Posted by Rpep

Yes, the pipe comes down from the drain like a "J' then loops back over to another pipe. This other pipe goes upward and that is where the AAV is located. I can provide a picture.

Yes, please, post photo. Thank you

Are you sure you don't have a crack in the female adapter that the aav screws into? I have seen aavs fail(stuck closed and open)however if you have replaced it twice, odds are the problem is elseware. Please let us know what you find.

Quote:

Originally Posted by mygirlsdad77

are you sure you dont have a crack in the female adapter that the aav screws into? I have seen aavs fail(stuck closed and open)however if you have replaced it twice, odds are the problem is elseware. Please let us know what you find.

At the moment, AAV is working. I can't figure out why 2 different bathroom's within 7 months would have a AAV fail. Let alone the fact that I bought a brand new one that didn't work? Any suggestions? Could it be a crack in the pipe? Maybe it is just my luck. At any rate, thanks for all the suggestions. I will be back if this doesn't continue to work.

Just glad the smell is gone, hope it stays that way. If it comes back , then you come back and we will try to help.

1 Attachment(s)

Quote:

Originally Posted by milo dolezal

yes, please, post photo. Thank you

Here is the photo you requested.

Attachment 13104

Quote:

Originally Posted by mygirlsdad77

just glad the smell is gone, hope it stays that way. If it comes back , then you come back and we will try to help.

Ok, I am back. It worked for a few hours. Then the smell started to come back again. This morning it is back to where we were yesterday. I guess our next step would be to replace all pipes under the sink? Believe me if we would have known that this is how they do manufactured homes, we would have made sure it was vented out, not in the home. This is a total pain.
Thanks

I have stupid question: is that really AAV vent you are using ? Our "Oatey" brand AAV vents look differently...

Do this: take your AAV vent. Cup your hands around it and put it to your mouth. Now, try blow air through it - outward. Than, cup your hand around the vent and try to suck air in. Come back and tell me what it does.

Quote:

Originally Posted by Milo Dolezal

I have stupid question: is that really AAV vent you are using ? Our "Oatey" brand AAV vents look differently.....

Do this: take your AAV vent. Cup your hands around it and put it to your mouth. Now, try blow air through it - outward. Than, cup your hand around the vent and try to suck air in. Come back and tell me what it does.

According to the box (it came in a AAV kit) it is a AAV. We bought a totally other AAV and it didn't work either. Smell still came in with it. Could there be a crack in the pipe or something that won't let it work properly?

If there is a crack, it would most likely be where you screw in the aav. If it were in the drain portion of the pipe it would leak water. Im not a big fan of aavs. I would rather see any and all vents externally vented. But this is how most prefabbed houses are done(save money) Maybe try removing the aav and installing a plug(temorarily), make sure there is water in the trap and don't run any water in any other fixtures in the house for half day or so and see if the smell goes away. If it does, then problem is in aav(not likely), if it doesn't we need to start looking at other sources for the problem.

So how did it work out? BTW, another source of smell is a bio-film that develops on the inside of the pipe before the P-trap. However, it's unlikely that such a film develop after only 2 years.